I would allow them to break their lease.

Lease options?

Do I just simply “assign” the Lease Option?

I will be getting a rent roll and lease agreements to confirm, but assuming they haven't lied about the rental income then the purchase price I'm getting this property for pencil's out. 

I hired a property management company to handle the lease/collection.

Just as they will evict, they will need to turn it around and lease it to another tenant. 

Does anyone know where I can get a decent template for a garage/storage lease agreement.

If the unit is vacant, how can they guarantee a price based on the rent unless you delay the closing until the lease is signed?  

There’s no one on a master lease so their each only responsible for their rooms but no one responsible for the rest of the house.

If you are looking for short term / immediate income, I would recommend fix and flips, wholesaling or lease options.